A new chart-based technique for parsing ill-formed input is proposed.
This can process sentences with unknown/misspelled words, omitted words or extraneous words.
This generalized parsing strategy is, similar to Mellish's, based on an active chart parser, and shares the many advantages of Mellish's technique.
It is based on pure syntactic knowledge, it is independent of all grammars, and it does not slow down the original parsing operation if there is no ill-formedness.
However, unlike Mellish's technique, it doesn't employ any complicated heuristic parameters.
There are two key points.
First, instead of using a unified or interleaved process for finding errors and correcting them, we separate the initial error detection stage from the other stages and adopt a version of bi-directional par...